/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Parameterization/MeshRegionGraph.h
This method leaves theFMeshRegionGraphin an invalid state, and should only be used as a means to avoid memory copies while extracting the triangle sets from aFMeshRegionGraphthat will then be discarded
list of triangles in a Region
[TArray](API\Runtime\Core\Containers\TArray)< int32 > && MoveRegionTris ( int32 RegionIdx )